Automatic power control for pneumatic-despatch apparatus.



B.- A. PORDYGB & G. S. JENNINGS. AUTOMATIC POWER CONTROL FOR PNEUMATIC DESPATGH APPARATUS.

APPLICATION FILED M19, 1906.

Patented Nov. 21,191

UNITED STATES: ormcn. 1

EDMOND A. FORDYCE, 0F BOSTON, AND CHESTER S. JENNINGS, OF BROOKIIINE, MAS- SACHUSETTS, ASSIGNORS TO LAMSON CONSOLIDATED STORE SERVICE COMPANY,-OF

NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

AUTOMATIC POWER CONTROE FOR PNEUMATICi-DESPATCH APPARATUS.

Specification of Letters Patent. Patented NOV. 21, 1911. Application filed March 9, 1906. serial No. 305,112. A

lqoZl whom it may concern: 7

-{Be it known that we, EDMOND A. F011 DYoE, of Boston, Suffolk county, State of Massachusetts, and CHESTER S. JENNINGS, of Brookline, Norfolk county, State of Massachusetts, have inyented certain new and useful Improvements in Automatic Power Control, for Pneumatic-Despatch Appa-- ratus, of which the following 1s a specification.

Our invention relates to improvements in automatic power control adapted to use in pneumatic despatch tube systems; I

The principal object of our invention is to provide means for controlling and maintaining a predetermined working vacuum in said systems by increasing or decreasing the power in proportion to the working demands upon said systems thereby securing economy of power. This object is accomplished by utilizing any variation in the vacuum, to operate upon a piston, which simultaneously throws in or out of opera-' tion any or all of a plurality of pressure maintaining members furnishing power to the system. v

In the accompanying drawings which illustrate two forms of construction embodying our invention, Figure 1 is a diagrammatic view of the device partly in section,

'in electrical connection with pressure maintaming motors. Fig. 2 1s a modification,

plan view partly in section, of the device showing means for regulating the pressure"- controlled switch.

Like letters of reference refer to like-parts in the two views.

The pressure-controlled switch comprises the cyllnder A mounted on the base B having mounted therein the piston D attached to the piston rod F. The piston D is made fluid tight by snap ring E fitted therein. The rod F is adapted to reciprocate in bearing I and is prevented from turning therein by the pin H mountedlin the slot G and fixed to said bearing I. On the lower threaded end of the piston rodF is screwed the weight J. Inserted in the opposite end of the cylinder A is the vacuum pipe- G which supplies pressure to the cylinder. Fixed to the piston rod F is the bridge strip K which is adapted to slide or recip particularly.

rocate upon the contacts X, L, L and L which are attached to the base B. The contact X is connected with the line wire M; 4

the contact L 'is connected by thev'ire P with one end of the coil of the solenoid R'.

the other end of the coil being connected with the line wire M. The contacts L and L are connected respectively by wires P and P with the ends of the coils of the solenoid switches R and R the other ends of noids N N N that is, in motor 1 for example, one brush connects directly with the wire M while the other brush is connected by the wire S with a contact T of the switch N. The other contact T of switch N is connected by the wire V with line wire M; it will thus be seen that the motors 1, 2 and 3, together with their switches N, N? and N are in multiple and that with all of these switches closed, the predetermined Working vacuum is maintained for the maximum demands upon the system. When the vacuum in the system increases, due to a diminution of the load, therebylifting the piston D, causing the lower bridge piece K to be moved away from contact L, the motor #lis cut out. As will be obvious, a further variation of vacuum in the same direction will cut out first motor #2 and finally motor #3. When the piston D descends from its highest position due to a decrease in vacuum caused by an increase.

are connected respectively with switches- N, N and N by wires P, P and P the operation being identical with the device shown in Fig. 1. v

'Having thus described the nature of our invention and set forth a construction embodying the same, what we claim as new and desire to secure by Letters Patent of the United States is:

1; In an automatic pressure controller, an electric circuit including a switch actuated by fluctuations of pressure in the system, a plurality of pressure-maintaining motors in multiple connection with said circuit, and switches in the difierent motor circuits in multiple connection with the switch actuated by fluctuations of pressure operating to cut in or out progressively the motors to maintain a constant pressure in the system.

2. In an automatic pressure controller, an electric circuit including a pressure-coin trolled switch, a plurality of pressure-maintaining motors in multiple connection with said circuit, solenoid switches in the different motor circuits with their solenoids in multiple connection with the pressure the motors to maintain a constant pressure in the system.

3. In an automatic pressure controller, a pressure-controlled switch, a plurality of pressure-maintaining motors operating to generate and supply pressure to operate said pressure-controlled switch, a plurality of switches with each one controlling one of said motors, and means connecting the motor-controlling switches with said pressure-controlled switch whereby said pressure-controlled switch actuated by fluctuations in the pressure generated by said motors operates said motor-controlling switches to cut in or out progressively the motors to maintain a constant pressure at the pressure-controlled switch.

In testimony whereof, we have signed our names to this specification in the presence of two subscribing witnesses, this 27th day of February A. D. 1906.

EDMOND A. FORDYCE, CHESTER S. JENNINGS. Witnesses:

GEORGE L. HAGER, E. LAMONT. 

